This invention relates to gear drives, and particularly to an apparatus for dividing and spreading the thrust loads to which a shaft is subject.
In gear drives a shaft will often be subjected to thrust loading by reason of the machine or other equipment being driven. Thrust bearings are commonly employed to accommodate the thrust loads. Thrust bearings are typically mounted to react against an end of the shaft remote from the origin of the load. The thrust bearing must be sized for the load which it will be expected to encounter. Generally, the diameter of the thrust bearing will increase as its capacity increases.
There are instances in which it is impossible to mount a thrust bearing of sufficient size in the desired position at the end of the output shaft. One example of such an instance involves a gear drive which includes two parallel driven output shafts which must be located in close proximity to each other and which are both subject to thrust loads. In such an arrangement the two parallel output shafts may not have sufficient clearance between them to accommodate a large diameter thrust bearing at the end of both shafts.
The apparatus of the present invention is directed to solving the problem accommodating thrust load in such an arrangement where the typical large diameter thrust bearings are unusable. The apparatus solves the problem by dividing the thrust load on one of the output shafts between two separate gear trains and moving the thrust loads radially outward from the centerline of the output shaft to positions where the thrust can be taken up in large thrust bearings provided on shafts of each of the two gear trains. The apparatus also includes means to equalize the thrust loading between the two gear trains and to reduce the speed at which the load is absorbed.